[Evaluation of distances in yeast phosphoglycerate kinase molecules using saturation effect ESR spectra at 77 K]

Distances between a spin label attached to the single SH-group of yeast phosphoglycerate kinase and paramagnetic ions bound to the active centre in the complex with ATP were estimated by means of saturation of ESR spectra of the spin label at 77K. The calculations were performed for the ions with g-factor approximately equal to the g-factor of the spin label on IBM PC/AT. Distances between the SH-group of phosphoglycerate kinase and the middle of the active centre of the ATP binding site were estimated by using the stable complex of CrATP.